main {
    flex: 1;
    color:#444;
    background: #eee;
}
nav, aside {
    flex: 0 0 20%;
    background: #60AAEF;
}
nav li a {
    display: block;
    color: #fff;
    padding: 8px 0 8px 16px;
    text-decoration: none;
}
nav li a.selected{
    background-color: #eee;
    color:#444;
}
voice {
    margin-bottom: 20px;
    display: block;
}
.right-part {
    padding: 20px;
}